I Look Better in Basic Black - S1-E28
Factual error: The American women the SS brings into camp claim to be entertainers having performed for troops. The series is allegedly set in 1942. Before June 6th, 1944 there were no allied troop concentrations in central Europe, certainly not in Germany, and very certainly none of a size and security rating the USO (or probably rather its predecessor organization, since the USO was founded in 1941 and would not have been fully operational yet) would send a troupe of female entertainers to.
Praise the Fuhrer and Pass the Ammunition - S2-E19
Factual error: In the ammunition dump, a sign saying "Warnung Hoche Sprenggefahr" can be seen. That is not correct German. First, and foremost, it must be "hohe" and not "hoche", the latter form does not exist. Secondly, the word "Sprenggefahr", while not formally wrong, was never used in German. Depending on what the meaning of the sign is supposed to be, it must either be "Explosionsgefahr", if the overall danger of an explosion is meant, or if the property of the ammunition of being explosive is meant, it should be "Hochexplosiv." If the general presence of explosive material is being warned of, "Explosivstoffe" or "Hochexplosives Material" would be possible.
Factual error: Erica says she has a plane to take Klink and her to Argentina. The only transatlantic airplane in Germany at that time was the FW-200 Condor, whose military value would have made it hard to requisition even for an SS Gruppenführer (which would be the real rank a "General" would hold in the SS, different mistake), let alone for his wife. Plus, even the FW-200 could not have made it even to the Brazilian coast without a refueling stop somewhere along the African west coast, which would have been a problem, because Germany had no possessions there. Klink, being a Luftwaffe (Air Force) officer, should have at least been suspicious of that plan, even if he didn't know all the details off the top of his head.
Factual error: Klink and Hogan sit behind each other in the P-51 they try to steal. The P-51 is a single-seat airplane, the only twin-seat P-51 are trainers. A trainer would not be at the flight line with the regular airplanes, and if a trainer would actually scramble with the others, it would at least arouse suspicion.
Factual error: Throughout the entire series, there are often uniforms that are incorrect; an oversized eagle on German Visor Caps appears most often.
Factual error: Hogan and his men are in Berlin to capture a traitor. They arrive at the Hotel Berlin in an ambulance and park near a K2 phone booth, something only found in England and its colonies, certainly never in the heart of Nazi Germany. (00:13:55)
The Kamikazes Are Coming - S6-E20
Factual error: When Hockstetter shows up in Klink's office he has two SS soldiers with him. One has a coat on with a general's rank insignia.
Factual error: While the show always made it winter time by having snow on everything (salt piles strewn about) and icicles on all the windows, this episode has an actual date of occurrence, June 6, 1944. They help to solve the snow on the set by taping the whole episode inside. However, the windows still all have the ice formations on them. It's late spring.
The Top Secret Top Coat - S2-E29
Factual error: In Klink's quarters, there's an (obviously fake) banana in the fruit bowl. Bananas were luxury items in Europe in the 1940s, and certainly so in war-torn Germany. The majority of Germans didn't have access to exotic fruit until the 1960s, and fake fruit of this type wasn't available then either.
Factual error: Frankel suggests manipulating the missile's gyroscope, and Hogan suggests an electromagnet as means to do it, which is later implemented. Gyroscopes however are not affected by any magnetic force, which is what makes a gyroscopic compass superior to a magnetic one in many situations. To enhance that effect, gyroscopes are deliberately built out of materials with as little magnetic susceptibility as possible. A large electromagnet next to the missile could potentially cause all kinds of havoc with all kinds of parts of the missile guidance and control, but the gyroscope itself would not be among them.
Factual error: The motorcycle courier coming in wears sunglasses that are definitely newer than 1942. Sunglasses with domed, wrap-around lenses were not invented in the 1940s.
Kommandant of the Year - S1-E3
Factual error: A sharp brass cone has been put over the spike on Klink's Pickelhaube, so Hogan can pin the page torn from the Geneva Convention onto it. The real spike of a Pickelhaube has concave slopes, and it isn't pointy enough to pin a piece of paper onto it.
How to Catch a Papa Bear - S4-E3
Factual error: In the tunnel Hogan loads a magazine into a US issue .45 pistol and points it at Myra, but he never chambered a round and didn't cock the hammer on the pistol. The .45 pistol in WW2 was single action. For a single action pistol to fire, a round needs to be chambered and the hammer has to be cocked manually before the trigger is pulled and the pistol to fire. (00:22:00)
Factual error: Hogan calls the radio detection truck "radar" when he orders the SS guard to switch it off. From other episodes, we know that Hogan knows what radar is, and back then, the difference between radio homing equipment and radar was even clearer to people than it is today, because radio homing was an established technology, while radar was brand new, and most people were not even aware it existed.
Factual error: Baker picks up a lot of static in his radio, then suddenly signs off and says "Sounds like the radio detection unit picked up our signal." Unlike radar, radio signal homing relies entirely on measuring the signals emitted by the transmitter that is tracked. It works by comparing the strength of the signal arriving at each component of an array of directional antennae. The process is completely passive and does not cause any alteration of the signal measurable at either receiver or transmitter at all, and certainly not any audible interference or humming.
Axis Annie - S3-E23
Factual error: After Carter realises Hogan got the envelope off so fast, Newkirk says "Speedy Gonzales." 'Hogan's Heroes' was supposed to take place from 1942 to the end of the war. Speedy Gonzales first appeared in "Cat Tails for Two" in 1953.
Factual error: The first episode of Hogan's Heroes (Season 1) begins with a view of Stalag 13 and a title: "Germany, 1942." That said, Colonel Hogan indicates in several episodes that he has worked in the Pentagon although construction of the Pentagon was actually completed in 1943.
Factual error: As the staff car comes up the street, there are a number of neon signs lit up, as well as store fronts. This is wrong as during the night in wartime Europe, such lighting would be dark to avoid night bombing.
Factual error: The cover of the plan for Unternehmen Hannibal is marked "SEHR GEHEIM." That phrasing does not exist in German. The correct term would be "streng geheim".
Factual error: On the map in Klink's office, the nearest town's name is Hamilburg. This a misspelling, as the real name is Hammelburg.
Answer: Nimrod's actual identity was never revealed in the series. It was only known that he was a British intelligence agent. Nimrod was not Colonel Klink. Hogan had only implied it was him as a ruse to get Klink returned as camp commandant, not wanting him replaced by someone more competent who would impede the Heroes war activities. The term "nimrod" is also slang for a nerdy, doofus type of person, though it's unclear why that was his code name.
raywest ★
"Nimrod" is originally a king and hero mentioned in the Tanach and taken into the Bible and the Koran. His name is often used in the sense of "stalker," "hunter," and sometimes figuratively as "womanizer" as in "hunter of women." I've never seen it used to denote a nerdy person, and although I cannot disprove that connotation, I think given his role, the traditional meaning is more likely the intended one.
Doc ★
It's widespread enough that Wikipedia has an entire section on it: https://en.wikipedia.org/wiki/Nimrod#In_popular_culture